Depends on whether you need a nanny as a stop gap until you get into daycare or if you are looking for someone to be with you for a few years. In the former, sure, roll the dice. In the latter, I would not do this. Then you will need to mess with leave for her, potential time off towards the end for appointments or illness, whether she comes back or not after the baby - or wants to bring the baby; or is dealing with sleep deprivation while caring for your baby.
Yep, it's awful, but I would be shocked if other employers or ONE employee that rely on that employee fully to make their "business" run would do any differently. It's just such a different situation from an office that can spread work out a bit while someone is out or even hire a sub if needed.